A CD is available from Popular Mechanics for each MB model year with a $19.95 price tag. Very reasonable! Operation and troublehooting data for all ECUs is available on it. It has codes for all modules as well as repair info. For a single car owner and DIY, this is hard to beat. Here's the link: (scroll down the page abit!)
You can check my page for codes for my car. Strictly speaking these will not be the same as yours, but there is alot of commonality across the model years. Thus many codes are the same.